Urea coated stiffening sheet



Dec. 11, 1962 J. H. GAQUIN ET AL 3,058,130

UREA-comm STIFFENING SHEET Filed Sept. 17, 1959 ABSORBENT TISSUE BASESHEET HAVING RMOPLASTIC REGNANT FIG. 4

United States Patent Ce 3,068,130 UREA COATED STIFFENING SHEET JohnHarold Gaquin, Haverhill, and Ronald W. Morse, Newton, Mass., assignorsto Beckwith-Arden Inc., Dover, N.H., a corporation of New HampshireFiled Sept. 17, 1959, Ser. No. 840,667 1 Claim. (Cl. 154--46) Thisinvention comprises a new and improved sheet material for stiffeningparts of shoes and which, although coated or impregnated with apartially condensed and normally tacky urea compound, is, in fact,non-tacky in handling, storage and shipment and until ready for actualassembly in a shoe upper.

Sheet material carrying such urea compounds have been used successfullyheretofore in stiffening box toes and counters but the material has beensubject to the very serious fault that in warm and humid weather it willturn tacky, making it inconvenient and unpleasant to handle anddifficult to separate when packaged in stacked formation.

The present invention solves this long-standing problem and makesavailable a stiffening material that has also other unexpectedadvantages. In one aspect the invention consists in covering orlaminating upon the urea-carrying surfaces of the base sheet a porous,absorbent tissue or membrane. This is applied so that it blends andmerges with the sheet material and its effect is completely to mask alltrace of tackiness which would otherwise be due to the presence of theurea compound. If the sheet material is coated on one surface only withthe urea compound, it is necessary to cover only that surface of thematerial with the tissue. If the material is impregnated or coated onboth surfaces, the tissue is applied to both surfaces thereof.

The material in that form may be handled as so much dry fabric havingappreciably no tackiness and no tendency to block when packaged in theform of stacked blanks.

The urea component of the material of our invention is caused to undergocondensation or polymerization to a final hard insoluble-infusible stageby the action of a catalyst. Resins of this type are well-known in theart and one which is suitable for purposes of this invention is awater-soluble A-stage urea formaldehyde resin, such as Urac 180 sold byAmerican Cyanamid Company, and which may be catalyzed effectively with asolution of ammonium chloride. It has been found that the presence ofthe porous tissue lamination of our improved stiffening material has theimportant advantage of retaining the liquid catalyst upon and in themost effective position for activating the urea compound and causing itsfinal polymerization to take place. That is to say, the tissue beingporous and absorbent tends to prevent the liquid catalyst from runningoff the impregnated base sheet and instead holds the catalyst evenlydistributed against the incured resin, thus promoting a much more evenlycured piece of stiffened material.

These and other features and characteristics of the invention will bebest understood and appreciated from the following disclosure of apreferred manner of preparing the sheet material as shown in theaccompanying drawings in which,

FIG. 1 is a diagrammatic view suggesting the steps of preparing sheetmaterial with a single coated surface.

FIG. 2 is a similar view suggesting the steps of preparing sheetmaterial impregnated or coated on both surfaces.

FIG. 3 is a plan view of a box toe blank embodying the invention.

FIG. 4 is a view in cross section on an enlarged scale showing thecomponent parts of the blank of FIG. 3.

The base sheet fabric employed may be double or single napped flannel,burlap, felt, or the like and in FIG.

3,068,130 Patented Dec. 11, 1962 1 this is shown as being drawn from acoil 10. From this it is led over an applying roll 11 partially immersedin a bath of partially condensed urea formaldehyde solution which iseffective to coat the lower surface of the sheet. The coated sheet thenpasses to a dryer 12 wherein the liquid coating is partially dried sothat the fabric issues from the heater in a slightly tacky condition. Itthen passes between squeeze rolls 14 and at this point a web of tissueis drawn from a coil 13 and combined with the still tacky sheet. Fromthe squeeze rolls 14 the laminated sheet is wound into the coil 15. Thetissue drawn from the coil 13 as already stated is porous, soft andabsorbent so that when pressed against the tacky surface of the basesheet it merges and blends into it with permanent adhesion.

Substantially the same process is illustrated in FIG. 2 except that inthis case the sheet material drawn from the coil it) is completelyimmersed in a bath 16 of urea solution so it emerges with both surfacescoated. From the bath 16 the coated material passes through the heater12 wherein both surfaces are partially dried to a condition oftackiness. The sheet is then passed between squeeze rolls 14 and at thispoint tissue drawn from the coil 13 is applied to the lower surface ofthe sheet while similar tissue is drawn from the overhead coil 17 andapplied to the upper surface of the sheet. Finally the laminatedmaterial is wound in a coil 18.

The sheet material thus prepared may now be cut into blanks for use instiffening box toes or counters. A box toe blank as shown in FIG. 3wherein the base textile fabric 20 is shown has united to a coextensiveply 21 of tissue, the latter being shown as partially separated from thebase fabric. The blank, thus prepared, may be shipped and handled asconveniently as a piece of lightlysized fabric. When ready for actualuse it may be brushed or dipped in an ammonium solution and this isdistributed over the entire surface of the blank and retained in and bythe porous and absorbent tissue ply 21 in the most favorable positionfor causing rapid final polymerization of the urea compound andhardening of the blank in the shape which has been imparted to it by theenclosed last.

While we have referred to urea formaldehyde as a satisfactory anddesirable stiffening compound, it could be within the scope of theinvention to employ any other urea solution or compound having similarcharacteristics, such as thiourea-aldehyde, melamine-aldehyde orphenol-aldehyde.

Ammonium phosphate, phosphoric acid, hydrochloric acid or theirequivalents may also be employed as the catalyst component if desired.

Suitable tissues for purposes of this invention are readily available inthe open market and may be described as thin, light weight andtranslucent as well as porous and absorbent in texture, more absorbentthan the base fabric. The tissue may be of paper stock, or cotton fabricor other cellulose sheet material of medium weight or lighter.

Where thin tissue is used it has a tendency to blend and merge with thebase sheet so completely as to become substantially invisible and undersuch condition it is difficult for the user to determine which side ofthe blank should be located in contact with the shoe lining. To obviatethis difficulty we employ a tissue differently colored from theunderlying base sheet to indicate the urea-carrying surface of theblank.

As a further important embodiment of our invention We employ a basesheet impregnated with a thermoplastic stiffening compound. In thisinstance the sheet material drawn from the coil 10, instead of beinguntreated cotton, for example, may carry such thermoplastic component ascellulose acetate or nitrate, ethyl cellulose, methacrylate,

vinyl acetate, butyral or chloride or combinations of the same withnatural gums or waxes. In using material of this kind the blank isactivated by the application of the liquid catalyst, placed in the shoeupper and molded under heat and pressure while the urea component isconverted by condensation to its hard insoluble stage. The action of theurea compound is to supplement the more brittle stiffening of thethermoplastic component and obviate the formation of cracks in thefinished toe box or counter, providing a box toe in the shoe superior inrespect to life and texture to those heretofore known.

Having thus disclosed our invention and described in detail illustrativeembodiments thereof, we claim as new and desire to secure by LettersPatent:

References Cited in the file of this patent UNITED STATES PATENTS2,277,941 Almy Mar. 31, 1942 2,446,414 Farrell et a1 Aug. 3, 19482,758,045 Heaton et a1 Aug. 7, 1956

